• Length-wise direction on a ship is fore and aft.
• Cross-wise is athwartships.
• The front of the ship is the bow.
• The rearmost of the ship is the stern.
• A ship is divided in half length-wise by a center line.
• Starboard: right side of the ship.
• Port: left side of the ship.
• The extreme width of a ship, usually in the midship area, is called the beam.
• The backbone of the ship is called the keel.
• Frames running paralleled with the keel are called longitudinals.
• The interior of a ship is divided into compartments by vertical walls, called bulkheads.
• The plates that form the ship's hull are called strakes.
• The vertical distance from the bottom of the keel to the waterline is the ship's draft.
• The distance from the waterline to the ship's main deck is called the freeboard.
• The floors of the ships are called decks.
• Bulwarks are a sort of solid fence along the gunwale of the main (weather) deck. The bulwarks are fitted with freepoints (called scupers) to permit water to run off.
• Levels- A term used to designate decks. The main deck is called the first deck. The first level above that is called the 01 level, the next deck above that 02, and so on. The deck below the main deck is the 2nd deck, then the 3rd deck and so on. Refer to figure 8-1 on page 8-2.
• Superstructure is the solid part above the ship's main deck.
• The mast and stacks above the superstructure are referred to as the ship's top hamper.
• Compartment designation/Deck Numbering System: Almost every space in a ship has a designation. If you are not familiar with compartment designation, you need to refer to fig. 8-12 on pg. 8-11, and Table 8-1 on pg. 8-12 of the BMR.

Ship Categories

• CVs: multipurpose aircraft carriers
• CVNs: multipurpose aircraft carriers/nuclear propulsion
• BBs: Battleships (all decommissioned)
• CGs/CGNs: They are medium sized general utility ships
• DDs: Destroyers are multipurpose ships. They are fast with little armor.
• DDGs are similar to the DDs, but have a guided weapons system.
• FFGs: Frigates are used for open ocean escort and patrol. Frigates resemble destroyers in appearances, but they are slower, have only a single screw, and have less armament.

All Amphibious warfare ships have the letter L as a designation, i.e., LSD, LST, LPD, LHA.

• LHAs are amphibious assault ships that embark, deploy, and land a marine battalion; Land helicopters, landing craft, and amphibious vehicles.
• LPD's: amphibious transport dock. They are versatile ships. They transport amphibious cargo as well as transport troops and equipment.
• LHDs: The Wasp class LHDs are the largest amphibious ship in the world. They are designed to embark, transport and land 2,000 troops and their equipment. They also have the capability to assist in antisubmarine warfare.
• LSDs: Dock Landing Ship. Also designed to transport troops and launch a variety of amphibious craft and vehicles.
• LSTs: Tank Landing Ship. (All decommissioned) They were developed during World War II. They were capable of transporting troops, tanks, and supplies.
• LCCs: Amphibious command ships. They provide amphibious command and control for major operations.
• MCMs: Mine Warfare Ships are mine countermeasures. The are designated to clear mines. The Avenger class ships use sonar and video systems, cable cutters, and a mine detonating device. The ship's hulls are made of fiberglass or wood.

• AOEs: Fast combat support ships. Supplies fuel and ammunition. Also can supply dry and refrigerated stores.
• AOs: Auxiliary Oiler: Supplies fuel and jet fuel.
• AEs: Ammunition ships supply ammo & missiles to the fleet.
• ARSs: Rescue and Salvage ships. They have 4 parts to their mission.
1. debeaching stranded vessels
2. heavy lift capability from from ocean depths
3. towing other vessels
4. manned diving operations.
• ATFs: Fleet Ocean Tugs- they have large cruising range and limited salvage capabilities.
• Replenishment at sea is the term applied to the transfer of fuel, ammo, or supplies from one vessel to another while underway. A separation of about 100 feet is maintained between ships. Fuel hoses on an AOE permit a separation of 200 feet.

Submarines

• The Navy deploys two classes of subs. (SSNs) Attack submarines and (SSBNs) Ballistic Missile Submarines.
• The mission of the (SSNs) nuclear attack sub is to locate and destroy enemy ships and subs.
• The mission of the (SSBSs) Fleet ballistic missile submarines deliver ballistic missile attacks from either surfaced or submerged condition.
• The Ohio Class sub is the largest undersea craft developed by the Navy. It has 24 tubes for Trident Missiles.
• The Seawolf class of fast-attack submarine: its stealthiness makes it the world's quietest sub.
• Early subs were names after marine life. The first SSBNs were named after persons well known in American History. The new SSNs are named after American cities.